Fluid power unit



March 16, 1954 z, RUBEN 'Re. 23,803-

I FLUID POWER UNIT Original Filed April 10, 1944 2 Sheet-Sheet 1 FIG! IIN VEN TOR.

zomzo D. RUBEN] Z. D. RUBEN FLUID POWER UNIT March 16, 1954 2Sheets-Sheet 2 Original Filed April 10 1944 FIGJO l 1 'll/11 ReissuedMar. 16, 1954 FLUID POWER UNIT Zorro D. Ruben, Chicago, Ill.

Original No. 2,498,451, dated February 21, 1950. Serial No. 530,416,April 10, 1944. Application for reissue February 16, 1951, Serial No.211,256

Matter enclosed in heavy brackets I: appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

20 Claims.

' cylinder block with the pistons reciprocating therein is rotatable,and wherein each piston is provided with a yoke that moves with it inits combined rotary and reciprocatory motion, said yoke acting tosupport the side thrust which would otherwise be communicated to thepiston by the driving member.

It is a further object of the present invention to provide an improvedarrangement for eiiecting the interconversion of the rotary andreciprocatory motion, which arrangement will provide for a simple andeflicient valve action in controlling the how of fluidinto or from thecylinder bore.

It is a still further object of the present invention to provide animproved and simple means for varying the output of the power unit aseither by varying the stroke of the piston or by a valve control whichvaries the eifect'of a constant stroke action of the piston, the desiredresult being obtained either by varying the inclination of an inclinedaxial cam that coacts with the pistons, or by varying the timing of thevalves with respect to the position of the rotary cylinder block withinwhich the pistons are reciprocated.

It is a still further object of the present invention to provide animproved connection between a rotary shaft and a rotatable cylinderblock carried thereby. In the preferred embodiment of the presentinvention the mechanism comprises a stationary cylinder casing from oneend of which a rotary power shaft extends. Within the casing the powershaft carriesa torque tube that extends approximately to the I oppositeend of the casing and there has a cylinder block secured thereto to becarried by the torque tube. The cylinder block in its rotation bringseach cylinder bore thereof successively into communication with intakeand discharge ports formed in the stationary part of the structure. Inone preferred construction means is provided for varying the angle ofinclination of the axial cam to vary the stroke of the pistons, thusvarying the output of the mechanim. In another preferred constructionthe inclination of the axial cam is maintained constant but the cam isangularly adjustable with respect to the intake and discharge ports tovary the phase relationship of the reciprocatory motion of the pistonand the circular motion of the cylinder block with respect to the ports.This phase relationship determines the position and direction 01'reciprocation of the piston at the moment that the cylinder [block]opens into communication with a port and at the moment communicationwith that port is closed, thus altering the output of the machine.

It is a still further object of the present invention to provide amechanical construction wherein the cylinder block is driven by a torquetube which surrounds the inclined axial cam that controls the positionsof the pistons in the cylinder bores as the cylinder block rotates.

By reason of the present construction it is possible to produce amechanism such as, for instance, a variable displacement hydraulic pump,which is exceedingly small and light in weight for given operatinpressure[;], especially pumps that operate at very high pressures, suchas two thousand pounds per square inch. Also, as a result of the presentconstruction, a small, light, high pressure pump may be built whereinthe advantages of a rotary cylinder block are combined with theadvantages of astructure wherein the side thrust of the pump pistonagainst the cylinder walls is eliminated by the employment of yokes suchas are used on pumps wherein the cylinder block is stationary.

The attainment of the above and further objects oi the present inventionwill be apparent from the following specification taken in conjunctionwith theaccompanying drawings forming a part thereof.

In the drawings:

Figure l is a longitudinal sectional view through a pump embodying thepresent inven- Figure 2 is a [longitudinal] sectional view taken alongthe line 22 of Figure 1 and looking in the direction of the arrows;

Figure 3 is an end view of the pump of Figure 2;

Figure 4 is a fragmentary sectional view taken along the line 4-4 ofFigure 1 with the outer casing omitted;

Figure 5 is a fragmentary sectional view taken along the line 5-5 ofFigure 1 with the outer casing omitted;

Figurefi is an end view of a yoke of the pump of Figure 1; I

Figure 7 is a side view of the same yoke;

Figure 8 is a view of the cam bearing surface of the swash plate ofFigure 1;

Figure 9 is a longitudinal sectional view through a pump of a modifiedconstruction embodying the present invention;

Figure 10 is a sectional view taken along the line I -H; of Figure 9;and

Figures 11 and 12 are, respectively, end and side views of one of theyokes used on the pump of Figure ['7] 9.

Reference may now be had more particularly to Figure 1. The pumpillustrated in Figure 1 comprises a stationary casing body I, circularin cross section, having peripherally spaced bolt holes 2 for receivingbolts or the like for mounting the pump as desired. A rotatable shaft 3is journalled in the body I in suitable bearings 4, and is constantlyurged in a direction leftward, as seen in Figure 1, by a compressedcoiled spring 5. A suitable shaft seal 6 held by a threaded nut 1 isprovided, as is usual. Within the body I the shaft 3 has a circularflange III on which is' splined a torque tube II. To secure the torquetube to the flange ID the flange is provided with axially extending ribsI3 (Fig. that extend into slots 14 in a short neck 15 formed in thetorque tube. The. torque tube is thus keyed to and rotates with theshaft 3. At its forward end the torque tube II has a bearing bushing 18secured thereto in any desired manner as, for instance, by means of apin 19 (Fig. 2) that holds the bearing bushing fixed in the torque tube.A cylinder block 2|) is secured in the forward end of the torque tube,in a manner to be presently described. The cylinder block is starshaped,having a plurality of arms 2|, in this instance seven, radiating from acentral hub, each of which arms has a longitudinally extending cylinderbore 23 therethrough. A cylinder block cover plate 24 is secured to thecylinder block by welding. The cylinder block cover plate 24 is splinedto the torque tube. For this purpose the periphery of the cover plate 24is provided with slots 21 that receive fingers 28 at the end of thetorque tube II. The cylinder block cover plate has openings 29 therein,each of which is located over one of the cylinder bores 23.

A stationary spindle 3| coaxial with the drive shaft 3 extends throughthe cylinder block cover plate 24 and through the cylinder block and isjournalled at its opposite end in a suitable ball bearing 32 in theflange ID of the drive shaft 3. The spindle 3| has a cam support 33located in a milled slot 35, being pivotally mounted therein as by a pin36. A pair of swash plate bearings 38--39 are rotatably mounted on thecam support bearing upon a variable axial cam 40 that is keyed to'thecam support 33. The variable axial cam 40 consists of a solid metallicring or disc that fits over and is keyed to the cam support 33 which ispivoted on .the pin 35 carried by the stationary spindle 3 I. Each swashplate bearing 38-39 consists of a ring or annulus that is free to turnon the cam support, being loosely fitted on the support and operates insliding surface contact with the variable axial cam 40.

Each cylinder bore 23 has a piston 44 reciprocable therein. Each pistonis part of a piston and yoke assembly that cooperates with the swashplate hearings to effect reciprocation of the piston upon rotation ofthe torque tube carrying the cylinder block. Each yoke, indicated at 45,is of a construction such as is shown more particua metal memberincluding inner and outer radial bearing surfaces'4l-43 and a[tangential] circumferential bearing surface 50. A thin flexible metalcar 52 is welded to each yoke, said ear having a perforation 53therethrough through which extends a piston connecting rod 54. Oneend-of the piston connecting rod is threaded into the piston, as maybeseen from Figure 1. The opposite end of the connecting rod has a bearingsurface 51 formed thereon said bearing surface being a portion of thesurface of a sphere. The yoke has a return ear 53 that has a tubularrear yoke bearing 60 projecting therefrom. The rear yoke bearing 50 isslidably mounted in a bore in the flange l0 and has a. piston returnbearing stud 52 slidable therein and urged outwardly by a compressionspring 83 the opposite end of which bears against a plug 64 threadedinto the rear bearing 50.

The swash plate bearing 38 has a number of pockets 68 formed therein,one opposite each piston. A floater pad 69 is located in each pocketbetween the swash plate and the bearing surface 51 at the end of theconnecting rod 54. Each swash plate also has a series of slots 10, whichadmit oil to the bearing surface between the swash plate and the floaterpad. The circular .floater pad 69 has a flat rear surface which slidesin a small ellipse on the swash plate bearing, and has a front surfacewhich is curved to receive the piston rod bearing 51. The swash platebearing 39 is similar to the bearing 33 and also has a floater padslidable thereon opposite each piston return bearing 62.

Each yoke bears upon and reciprocates on the inner surface of the torquetube and also slides between the bearing bushing I3 and the cylinderblock. The radial and [tangential] circumferentz'al bearing surfaces48-40 slide on the cylinder block as the piston reciprocates, in amanner to be more fully described as this specification proceeds.

The spindle 3| has an axially extending bore therein in which is mounteda control cam 15 near the end of a control shaft 16 that extends througha connecting bushing 11 bolted to a connection cover which is itselfbolted to the casing I by bolts 8|. The control cam 15 controls thepositions of two axially slidable control pins 8283 that bear againstthe cam support 33 and fix its variable angle of inclination.

The inner surface of the cover plate so has two arcuate grooves 8631therein forming orts or passageways, each of which extends throughalmost and which communicate with intake and outlet ports 33-90,respectively. The inner surface of the connection cover and the outersurface of the cylinder block cover are ground perfectly fiat so thatthe cylinder block cover 24 slides on the inner surface of theconnection cover 80, under pressure of the spring 5 aided by the fluidpressure within the cylinders.

An explanation will now be given of the mode of operation of the pump ofFigure 1. Rotation of the drive shaft 3 causes rotation of the torquetube I l, the yokes, the cylinder block cover plate 24, and the cylinderblock 20. The spindle 3i and the axial cam carried thereby arestationary in their adjusted position during rotation of the driveshaft. As the cylinder block and the yokes rotate, the bearing surface51 of each piston bears against the associated pad 69 on the swash plateand causes'the piston to reciprocate.

Each piston [54] 44 is moved into the cylinder by the engagement of thebearing surface 51 with its pad 69 whereas the movement of the pistonoutwardly of the cylinder is efiected by the yoke which is moved by thebearing 62 acted on by its associated pad. The swash plates 38-39 arefree to rotate on the variable axial cam W. The friction between theswash plates and the cam 40 is made very low. The pressure of the pad orpads on the swash plates causes the swash plates to turn with thecylinder block. [One of the contacting surfaces of each swash plate withthe cam II! is shaped to form a tapered land bearing as shown in Figures7 and 8 of my application Serial No. 490,957.] The bearing design ispreferably altered to permit rotation in either direction. Each pad,such'as 69, has a small elliptical movement in its cavity [69] 68 in theswash plate 38. At the same time the piston of any one cylindercommences to move outwardly in its bore the cylinder is in communicationwith the intake port 86 of the cover plate. When the piston reaches itsoutermost position the further rotation of the torque tube brings theassoelated cylinder bore into communication with the outlet port 81 sothat upon reverse movement of the piston, that is, movement thereof intothe cylinder, it discharges the contents of the cylinder through thedischarge port.

To change the delivery of each cylinder per revolution of the driveshaft it is merely necessary to change the inclination of the axial cam40, since the inclination of this cam determines the stroke of thepiston. To change the angle of inclination of the cam it is merelynecessary to adjust the control cam shaft I6. When the variable axialcam is in a plane at right angles to the axis of the drive shaft 3rotation of the drive shaft will produce no reciprocation of thepistons, hence no output of the pump.

Reference may now be had more particularly to Figure [8] 9 showing amodified form of variable delivery pump wherein the stationary axial camis at a fixed angle of inclination to the axis of rotation of thecylinder black and wherein the pump pistons have a fixed stroke, thevariation in intake or delivery being effected by changing the timingrelationship between the position of the piston and the opening orclosing of the intake and outlet ports. Insofar as the structure ofFigure 9 is the same as that of Figure 1 the same reference numeralshave been used and a further description thereof is not necessary atthis time. In Figure 9 the drive shaft, torque tube, and the cylinderblock are of the same construction, as in the pump of Figure 1. In thispump a spindle, indicated at III), which is angularly adjustable but ismechanically held stationary during operation of the pump, carries anaxial cam III which has swash plates [HZ-l I3] 113-113 thereon andfreely rotatable thereon. Each piston 44 is provided with a yoke H6 of aconstruction such as illustrated more fully in Figures 11 and 12 and11].

The yoke H6 of the pump of Figure 9 differs from that of the pumppreviously described essentially in that each yoke embraces three sidesof an arm of the cylinder block rather than only two sides as in Figures2. For this purpose the yoke H6 has U-shaped lugs Ill integral therewithor welded thereto which U-shaped lugs pro vide radial bearing surfaces8-! l9 and [tangential] circumferential bearing surfaces I20 thatembrace an arm of the cylinder block. In the pump of Figure 9 the yokeslides in its full length against the inner peripheral surface of thetorque tube. The yoke H6 has ears "-59 the same as the yoke previouslydescribed.

The piston rod 54 in the pump of Figure 9 has, at its outer end, aconical bearing surface I25 at the apex of which there is formed a ballseat or socket that receives a projection at the end of a floater padI26 that is free to turn on the conical surface I25. The opposite faceof the floater pad I26 bears against the swash plate bearing I I3 andslides thereon in a small elliptical path.

The valve arrangement in the pump of Figure 9 is identical with that ofthe pump of Figure 1, the connection cover 80 being provided with fluidpassageways the same as is illustrated in Figure 3.

Upon rotation of the drive shaft 3 of the pump of Figure 9 the cylinderblock is rotated and the stationary axial cam Ill causes the pistons toreciprocate in the cylinder block, the length of stroke being determinedby the inclination of the axial cam. Therefore each piston has a fixedstroke. During the rotation of the cylinder block each individualcylinder bore is alternately brought into communication with the intakeport and the discharge port, the timing being determined entirely by theangular position of the cylinder block. the pump it is merely necessaryto turn the spindle H0. Turning of the spindle llll counterclockwise, asviewed from the left hand side of Figure 9, will cause the piston 44 tomove inwardly within the cylinder bore. Others of the pistons will moveoutwardly. Thus, while in Figure 9, if rotation of the shaft is assumedto be clockwise, as viewed from the right hand side of Figure 9, thepiston 44 is at the end of its outward stroke at the time that thecylinder block has just passed out of communication with the inlet portand is about to pass into communication with the outlet port; acounter-clockwise adjustment of the axial cam III will change thisrelationship. When this adjustment has been made the piston will not bequite at the end 'of its stroke when the intake is closed and will stillbe making some of its intake stroke even after the discharge port isopened to the associated cylinder bore. Later, during the dischargestroke, the cylinder [block] will close its communication with thedischarge port and open communication with the intake port even beforethe piston has reached the end of its discharge stroke. Thus only partof the full discharge of the piston will take place while the associatedcylinder bore is in communication with the discharge port. By thisarrangement the output [of] or delivery of the pump is varied. In orderto get zero delivery it is merely necessary to turn the axial cam tosuch a position that the piston M will be in its mid position within thecylinder at the time that the cylinder passes from communication withthe intake port to communication with the discharge port. When thiscondition prevails the piston 44 will draw liquid from the intake portduring half of the I intake stroke and-will draw liquid from thedischarge port during the other half of the intake stroke. During thedischarge stroke the piston will discharge liquid back into thedischarge port during half of the discharge stroke and will dischargeliquid back into the intake port during the other half of the dischargestroke. For any other adjustment of the axial cam the piston 44 will beeffective for only a fractional part of its full stroke. In view of thefact that the cylinder block contains many cylinders the pistons of Inorder to vary the output of which are at any one time at differentpositions,

it may be seen that when the pump is operating at less than 100%capacity each piston may, during the ineffective fraction of its stroke,be delivering liquid to some other cylinder bore rather than to thedischarge port. Thus each piston and its associated cylinder bore willact as a pump during a fraction of its stroke and, during anotherfraction of its stroke will be driven by pressure developed in one ormore of the other cylinder bores. Because of the reversal of thedirection of pressure I have found it necessary that each yoke beprovided with the [tangential] circumferential bearing surfaces Iii-HIthat bear on opposite sides of the cylinder block arm. This means thatthe pump of Figure 9 can operate to pump liquids in either direction sothat either port l990 may be the intake port and the other be the outputor delivery port. When the mechanism is operatedas a fluid motor itsdirection of rotation may be reversed at will while the direction offlow of fluid to the motor remains unchanged.

In compliance with the requirements of the patent statutes I have hereshown and described a few preferred embodiments of my invention. It is,however, to be understood that the invention is not limited to theprecise constructions here shown, the same being. merely illustrative ofthe principles of the invention. What I consider new and desire tosecure by Letters Patent is:

1. Apparatus of the class described comprising a rotatable torque tube,means at one end of the tube for rotating it, a cylinder block securedin the opposite end of the tube and rotatable therewith, a shaftextending axially through the block and around which shaft the blockrotates, an inclined axial cam carried by said shaft within the tube,cylinder bores formed in the block around said shaft, pistons in saidbores, said block having openings between adjacent bores, and means-slidably connecting the pistons with said inclined cam, said meansbeing slidable in said openings and supported on and rotating with thetorque tube.

2. Apparatus of the class described comprising a torque tube, means atone end of the tube for rotating the tube, a cylinder block secured tothe opposite end of the tube and rotated thereby, parallel cylinderbores formed in the block, pistons reciprocable in the bores, astationary ported member against which the block slides, the cylinderbores being brought into and out of communication with the ports as theblock rotates, a stationary inclined axial cam within the tube, meansslidably connecting the pistons with the cam and means for adjusting theposition of the cam during rotation of the torque tube to alter theoutput of the apparatus per revolution of the cylinder block.

3. Apparatus of the class described comprising a torque tube, means atone end of the tube for rotating the tube, a cylinder block secured tothe opposite end of the tube and rotated thereby, parallel cylinderbores formed in the block, pistons reciprocable in the bores, astationary ported member against which the block slides, the cylinderbores being brought into and out of communication with the ports as theblock rotates, a stationary inclined axial cam within the tube, meansslidably connecting the pistons with the cam and means for rotatablyadjusting the position of the cam with respect to the ports of theported member while maintaining its axial inclination constant therebyaltering the positions of the pistons in the respective cylinder boresat the instant of covering and uncovering of the ports by the cylinderbores [so that the output of the pump is varied while the piston strokeremains constant].

4. Apparatus of the class described comprising a rotatable torque tube,means at one end of the tube for rotating it, a cylinder block securedin the opposite end of the tube and rotatable therewith, a shaftextending axially through the block and around which shaft the blockrotates, an inclined axial cam within the tube, means adjustablymounting said cam on said shaft for angular adjustment about an axis atright angles to the longitudinal axis of the shaft, and means extendingthrough said shaft for adjusting the angle of inclination of the camwith respect to the longitudinal axis of the shaft.

5. Apparatus of the class described comprising a torque tube, means forrotating the tube, a [star-shaped] cylinder block secured to one end ofthe tube and rotated thereby and having pro- :Iectinu arms forming theblock into a star-shape, parallel cylinder bores formed in the arms ofthe star-shaped block, pistons reciprocable in the bores, an inclinedaxial cam within the tube and means slidably connecting the pistons withthe cam, said last mentioned means extending between the tube and therespective arms and being supported in and axially slidable between thecylinder block and the torque tube.

6. Apparatus of the class described comprising a tube, a [star-shaped]cylinder block secured to one end of the tube and having projecting armsforming the block into a star-shape, parallel cylinder bores formed inthe arms of the starshaped block, pistons reciprocable in the bores, aninclined axial cam within the tube, means extending axially through thecylinder block for supporting the cam, and means slidably connecting thepistons with the cam, said last mentioned means including partssupported in and axially slidable between the tube and the arms of thecylinder block.

7. Apparatus of the class described comprising a rotatable torque tube,means at one end of the tube for rotating it, a cylinder block securedin the opposite end of the tube and rotatable therewith, a shaftextending axially throughthe block and around which shaft the blockrotates, an inclined axial cam carried by said shaft within the tube,cylinder bores formed in the block around said shaft, pistons in saidbores, means slidably connecting the pistons with said inclined cam,ports for said cylinders, means for turning the cam about the axis ofrotation of the torque tube while maintaining its angle of inclinationwith respect to said axis constant, to alter the position of the camwith respect to the ports, and means for locking said cam in itsadjusted position while permitting rotation of the torque tube.

8. A rotary pump comprising a casing, a ported end member closing oneend of the casing and having a port opening on the inside of the casing,a rotatable torque tube in the casing, a cylinder block at one end ofthe torque tube and rotated thereby in sliding engagement with theported end member, said block having cylinder bores extending from thatsurface of the block which is in sliding engagement with the ported endmemher and movable by the rotation of the tube into and out ofcommunication with the port of the member, means at the opposite end ofthe torque tube for rotating the torque tube, a stationary inclinedaxial cam entirely within the torque tube between said last named meansand the cylinder block, adjustable means extending centrally through theblock for supporting and holding the cam in adjustable relationship withrespect to the ported member, pistons reciprocable in the cylinderbores, and means for slidably connecting the pistons with the camwhereby the cam causes reciprocation of the pistons upon rotation of thetorque tube and the cylinder block, said connecting means includingsupporting yokes sliding on the torque tube and supporting the pistons.

9. A rotary pump comprising a casing, an end plate member for thecasing, said member having a port therein opening on the inside of thecasing, a rotatable cylinder block on the inside of the casing and insliding contact with the end plate member, means for rotating the block,said block having a cylinder bore therein eccentric with respect to theaxis of rotation of the block and which is brought into and out ofcommunication with said port as the block rotates, a piston reciprocablein the cylinder bore, an inclined axial cam in the casing forreciprocating the piston as the cylinder block is rotated, and means forrotatably adjusting the position of the cam with respect to the portwhile maintaining its inclination constant with respect to the axis ofrotation of the cylinder block thereby altering the positions of thepiston in the cylinder bore at the instant of covering and of uncoveringof the port by the cylinder block, [so that the output of the pump isvaried while the piston stroke remains constant].

10. Apparatus of the class described comprising a tube at least one endof which is open, a plate secured to the tube and extending across oneopen end of the tube, a star-shaped cylinder block located in the tubewith its center coincident with the longitudinal axis of the tube,cylinder bores in the respective arms of the star-shaped block, thelongitudinal axes of said bores being parallel to the longitudinal axisof said [tubes] tube, said block being secured to said plate, and portsleading to the cylinder bores.

11. In combination a [star-shaped] cylinder block having projecting armsforming the block into a star-shape, Parallel cylinder bores formedtherein, ports leading to the cylinder bores, means forming a radiallyoutwardly extending flange around the blockand united therewith, a tubewithin which the block extends and from which the arms of the block arespaced by the flange, the flange being secured to the tube.

12. In combination a [star-shaped] cylinder block having projecting armsforming the block into a star-shape, parallel cylinder bores formedtherein, means forming a radially outwardly extending flange around theblock and united therewith, a. tube within which the block extends andfrom which the arms of the block are spaced by the flange, the flangebeing secured to the tube, pistons in the bores, ports leading to thecylinder bores, an inclined axial cam in the tube, means slidablyconnecting the pistons with the cam, said means including partsextending between and supported in the space between the block and thetube and slidable in said space in a direction parallel with thelongitudinal axes oi the bores.

13. An axial cam mechanism comprising an enclosing casing having meansforming a surface having port openings on the interior of the casing, acylinder block in the casing, said block having cylinders formed thereinand having port openings in one end surface of the block being incommunication with the respective cylinders,

said end surface of the block being in engagement with the firstmentioned surface and the port openings in the block positioned tocommunioate with the said port openings in the easing upon relativemovement between the casing and block, a cam support member carried bysaid casing and extending through a hole in said cylinder block, anaxial cam supported by said support member, pistons in said cylinders,means forming a pressure transmitting connection between the pistons andsaid cam, and means forming a driving connection with said cylinderblock around the periphery of said axial cam, by means of which power istranslated between the pistons in said cylinders and said drivingconnection.

14. An axial cam mechanism comprising an enclosing casing having meansforming a surface having port openings on the interior of the easing, acylinder block in the casing. S id block having cylinders formed thereinand having port openings in one end surface of the block being incommunication with the respective cylinders, said end surface of theblock being in engagement with the first mentioned surface and the portopenings in the block positioned to communicate with the said portopenings in the casing upon relative movement between the casing andblock, a cam support member carried by said casing and extending througha hole in said cylinder block, an axial cam supported by said supportmember, pistons in said cylinders, means forming a pressure transmittingconnection between the piston and said cam, means forming a drivingconnection with said cylinder block around the periphery of said axialcam, by means of which power is translated between the pistons in saidcylinders and said driving connection, and a supporting radial. bearingfor the cam support member, said bearing being between the cam supportmember and the means forming the drivin connection.

15. An axial cam mechanism comprising a stationary enclosing casing, acam-supporting member extending inwardly from and locked to one end ofthe casing, an axial cam, centrally pivoted on said member, an adjustingmember extending inwardly from the casing and located and supportedwithin said supporting member, and means responsive to movement of thead- :iusting member to vary the inclination of the cam on saidsupporting member.

16. An axial cam mechanism comprising an enclosing casing having meansforming a surface having port openings on the interior of the casing, acylinder block in the casing, said block having cylinders formed thereinand pistons in the cylinders and having port openings in one end surfaceof the block being in communication with the respective cylinders, saidend surface of the block being in engagement with the first mentionedsurface and the port openings in the block positioned to make fluidcommunication with said port openings in the casing upon relativemovement between the casing and block, a cam-supporting member withinthe casing, an inclined axial cam supported by said member within thecasing, a tubular driving member for the cylinder block, said tubulardriving member being connected to the cylinder block and surrounding thecam, and a rotary bearing member between said tubular member and saidcam supporting member.

17. An axial cam mechanism comprising an enclosing casing having meansforming a surface having port openings on the interior of the eastivemovement between the casing and block, a

cam-supporting member within the casing, an inclined axial cam supportedby said member within the casing, a tubular driving member for thecylinder block, said tubular driving 'member being connected to thecylinder block and surrounding the cam, cam follower means riding onsaid cam and coupled to said pistons for imparting translatory motion tosaid pistons as the cylinder block is driven by said tubular drivingmember, and yielding means exerting an axial force between the casingand said tubular member to urge the cylinder block ported surfaceagainst the said first mentioned surface.

18. An axial cam mechanism comprising an enclosing casing having meansforming a surface having port openings on the interior of the casing, acylinder bloclcin the casing, said block having cylinders formed thereinand pistons in the cylinders and having port openings in one end surfaceof the block being in communicaarcuately ported valve surface, said lastmentioned port openings positioned to communicate with said fluid inletand outlet ports through said arcuately ported valve surfaces of saidvalve head member upon relative movement between the block and valvehead member, a stationary cam support member carried by said valve headmember and extending through an axial opening in said cylinder block, anaxial cam s pported by said cam support member, and pistons in saidcylinders co-acting with said cam so as to reciprocate in theirrespective cylinders asthe cylinder block rotates.

20. An axial-cam type fluid pressure translating mechanism comprising avalve head member at one end of the mechanism, a driving memtral axiswhich have openings at one end'communicable with said fluid inletandoutlet ports through said arcuately ported valve surfaces of said valvehead member, said cylinder block terminating in a surface which slidablyengages tion with the respective cylinders, said end surface of theblock being in engagement with the the first-mentioned surface and the,port Ope i'jings in the block positioned to make fluid comsaid tubulardriving member, a rotary bearing.

member between said tubular member and said casing, and spring meansexerting an axial force between the casing and said tubular memberthrough-a portion of said rotary bearing and in a direction to urge thecylinder block ported surface against the said first mentioned surface.

19. An axial-cam type fluid pressure energy translating mechanismcomprising a rotatable cylinder block, a. valve head member having anarcuately ported valve surface with fluid inlet and outlet portsthereat, said block having cylinders formed therein substantiallyparallel to each other and to a central axis, said cylinders having portopenings in one end surfacepf the block which surface is slidablyengaged with the the arcuately ported valve surface, pistons in saidcylinders co-acting with said cam to recip- References Cited in the fileof this patent or the original patent UNITED STATES PATENTS Number YName Date 1,427,740 Johnson Aug. 29, 1922 1,428,876 Bolllnckx Sept. 12,1922 1,746,335 Boyle Feb. 11, 1930 1,822,064 Sorensen Sept. 8, 19811,826,325 Paul .Oct. 6, 1931 1,938,735 Andrew's Dec. 12, 1933 1,945,391Benedek Jan. 30, 1934 1,947,902 De Stoutz Feb. 20, 1934 2,071,672Whitcomb Feb. 23, 1937 2,138,194 Pfauser Nov. 29, 1938 2,161,143 Doe eta1 June 6, 1939 2,188,035 Dauster Jan. 23, 1940 2,236,237 Hulsebos Mar.25, 1941 2,241,701 Doe May 13, 1941 2,284,109 Vickers May 26, 19422,345,446 Baker Mar, 28, 1944

